Switch

Abstract

A fixed contact includes a pair of conduction members that are arranged opposedly and in parallel to each other such that tip ends of the conduction members are oriented toward an opening, a support frame (pedestal member) that tiltably supports bases of the conduction members, a leaf spring (pressurizing member) that biases the conduction members in a direction in which the tip ends of the conduction members approach each other, and an outer frame (shielding member) that covers peripheries of the conduction members and the leaf spring and shields them from an outside electric field, the leaf spring is arranged on an outer side of the opposed conduction members, and the outer frame is engaged with the tip end of the conduction member, thereby maintaining an opening width between the tip ends of the conduction members at a predetermined width.

1. A switch comprising a blade-type moving contact, which is rotatably and pivotally supported and reciprocates such that a free end of the blade-type moving contact draws a rotation locus, and a fixed contact that has conduction members with which the moving contact comes into contact, wherein
 the fixed contact comprises
 a pair of the conduction members that are arranged opposedly and substantially in parallel to each other such that tip ends of the conduction members are oriented toward an opening, 
 a pedestal member that tiltably supports bases of the conduction members, 
 a pressurizing member that biases the conduction members in a direction in which the tip ends of the conduction members approach each other, and 
 a shielding member that covers peripheries of at least the conduction members and the pressurizing member and shields them from an outside electric field, 
 
 the pressurizing member is arranged on an outer side of the opposed conduction members, and 
 the shielding member engages with the tip ends of the conduction members, overcomes a biasing force of the pressurizing member, and maintains an opening width between the tip ends of the conduction members at a predetermined width. 
 
     
     
       2. The switch according to  claim 1 , wherein a tip end of the shielding member is engaged with a notch formed at the tip end of the conduction member, thereby maintaining the opening width between the tip ends of the conduction members at a predetermined width. 
     
     
       3. A switch comprising a blade-type moving contact, which is rotatably and pivotally supported and reciprocates such that a free end of the blade-type moving contact draws a rotation locus, and a fixed contact that has conduction members with which the moving contact comes into contact, wherein
 the fixed contact comprises
 a pair of the conduction members that are arranged opposedly and substantially in parallel to each other such that tip ends of the conduction members are oriented toward an opening, 
 a pedestal member that tiltably supports bases of the conduction members, 
 a pressurizing member that biases the conduction members in a direction in which the tip ends of the conduction members approach each other, and 
 a shielding member that covers peripheries of at least the conduction members and shields them from an outside electric field, and 
 
 the pedestal member is supported by a support conductor with a predetermined play so that the pedestal member is movable in a direction perpendicular to a plane including the rotation locus of the moving contact. 
 
     
     
       4. The switch according to  claim 3 , wherein the support conductor includes at its tip end a protrusion that protrudes in a direction from the bases toward the tip ends of the conduction members, the protrusion is fitted in a hole formed in the pedestal member, and a retaining member is fixed to a tip end of the protrusion, thereby movably supporting the pedestal member with a predetermined play. 
     
     
       5. The switch according to  claim 4 , wherein the retaining member is separated at a predetermined distance from the free end of the moving contact that is at a location where the moving contact most closely approaches. 
     
     
       6. The switch according to  claim 1 , wherein
 a plurality of the conduction members are arranged along a direction of the rotation locus of the moving contact, and 
 the pressurizing member has a comb-like shape having tooth portions the number of which corresponds to the number of the conduction members. 
 
     
     
       7. The switch according to  claim 1 , wherein the pressurizing member is of a thin leaf spring shape having a dogleg-shape in cross section, and a central portion of the conduction member is pressed by a top of the dogleg-shape. 
     
     
       8. The switch according to  claim 7 , wherein a projection that regulates a warp amount of the pressurizing member to a predetermined value is provided in a recessed side of the dogleg-shape in cross section of the pressurizing member. 
     
     
       9. The switch according to  claim 7 , wherein the pressurizing member is of a thin leaf spring whose midsection curves convexly toward the conduction member. 
     
     
       10. A switch comprising a blade-type moving contact, which is rotatably and pivotally supported and reciprocates such that a free end of the blade-type moving contact draws a rotation locus, and a fixed contact that has conduction members with which the moving contact comes into contact, wherein
 the fixed contact comprises
 a pair of the conduction members that are arranged opposedly and substantially in parallel to each other such that tip ends of the conduction members are oriented toward an opening, 
 a pressurizing member that biases the conduction members in a direction in which the tip ends of the conduction members approach each other, and 
 an outer frame that covers peripheries of at least the conduction members and the pressurizing member, 
 
 the pressurizing member is arranged on an outer side of the opposed conduction members, 
 the pressurizing member is of a thin leaf spring shape having a dogleg-shape in cross section, and a central portion of the conduction member is pressed by a top of the dogleg-shape, and 
 a projection that regulates a warp amount of the pressurizing member to a predetermined value is provided in a recessed side of the dogleg-shape in cross section of the pressurizing member. 
 
     
     
       11. The switch according to  claim 10 , further comprising a pedestal member that tiltably supports bases of the conduction members. 
     
     
       12. The switch according to  claim 10 , wherein the outer frame engages with the tip ends of the conduction members, overcomes a biasing force of the pressurizing member, and maintains an opening width between the tip ends of the conduction members at a predetermined width. 
     
     
       13. The switch according to  claim 12 , wherein a tip end of the outer frame is engaged with a notch formed at the tip end of the conduction member, thereby maintaining the opening width between the tip ends of the conduction members at a predetermined width. 
     
     
       14. The switch according to  claim 10 , wherein
 a plurality of the conduction members are arranged along a direction of the rotation locus of the moving contact, and 
 the pressurizing member has a comb-like shape having tooth portions the number of which corresponds to the number of the conduction members. 
 
     
     
       15. The switch according to  claim 11 , wherein the pedestal member is supported by a support conductor with a predetermined play so that the pedestal member is movable in a direction perpendicular to a plane including the rotation locus of the moving contact. 
     
     
       16. The switch according to  claim 15 , wherein the support conductor includes a protrusion that protrudes from the pedestal member in a direction from the bases toward the tip ends of the conduction members, the protrusion is fitted in a hole formed in the pedestal member, a retaining member is fixed to a tip end of the protrusion, and the pedestal member is movably supported via the protrusion and the hole with a predetermined play. 
     
     
       17. The switch according to  claim 16 , wherein the retaining member is separated at a predetermined distance from the free end of the moving contact that is at a location where the moving contact most closely approaches.